The present invention relates to a novel hydrogenated block copolymer which is a block copolymer of a vinyl aromatic hydrocarbon having a specific vinyl bonding amount and a conjugate diene compound, with the hydrogenation ratio controlled in a specific range. The present invention also relates to a block copolymer composition containing the block copolymer and a polyolefin based resin, or the block copolymer and an adhesion-imparting agent.
More specifically, the present invention relates to an impact resistant resin composition having excellent impact resistance, specifically low temperature impact resistance and molding processability; a soft resin composition having excellent softness, transparency, molding processability; and a flexible resin composition having excellent flexibility, elasticity and molding processability.
Moreover, the present invention relates to a viscous adhesive composition having well-balanced adhesion characteristics, such as adhesive power and retentivity, and excellent melt viscosity stability under heating at a high temperature.
Since a polyolefin based resin, in general, has excellent chemical resistance and mechanical characteristics, it is used widely for the machine parts, automobile parts, domestic products, various containers, or the like. However, due to lack of impact strength, in particular, impact strength at a low temperature, the application purpose has sometimes been limited.
Then, in order to solve the problem, a large number of proposals have been provided concerning addition of a rubber component to a polyolefin. For example, JP-B-47-26369 (The term xe2x80x9cJP-Bxe2x80x9d as used herein means an xe2x80x9cexamined Japanese patent publicationxe2x80x9d) discloses a method for improving the impact resistance by adding a styrene-butadiene block copolymer and a thermoplastic elastomer to a polyolefin based resin. Moreover, JP-A-6-172593 (The term xe2x80x9cJP-Axe2x80x9d as used herein means an xe2x80x9cunexamined published Japanese patent applicationxe2x80x9d) discloses a composition comprising a polyolefin based resin and a hydrogenated block copolymer. However, according to these methods, since an ordinary block copolymer is used, the balance between the impact resistance, in particular, low temperature impact resistance, and the molding processability such as thermal stability and flowability is not sufficient.
Furthermore, recently, development of a non-halogen based transparent polymer material is promoted as a countermeasure for the environmental issues. Particularly in the field of sheets and films, softness and transparency have been demanded to a polypropylene based resin, and attempts have been made for the improvement thereof. For example, JP-A-6-287365 discloses a composition containing a polypropylene and a hydrogenated diene based copolymer. However, a composition obtained by the method has poor transparency and insufficient processability.
In contrast, a hot melt type adhesive has been used widely in view of the environmental pollution and the work environment. As a base polymer for the hot melt type adhesive, a vinyl aromatic hydrocarbon-conjugate diene based block copolymer (SBS) is widely used. For example, JP-B-56-49958 discloses a viscous adhesive composition using such a block copolymer. However, the SBS generally has poor thermal stability, and an insufficient balance between the retentivity and the adhesive power, and thus the improvement thereof has been called for. As a method for improving the same, JP-A-64-81877 discloses an adhesive composition comprising a triblock copolymer and a diblock copolymer. Moreover, JP-A-63-248817 discloses an adhesive composition comprising a block copolymer obtained by coupling with a specific bifunctional coupling agent (a fatty series monoester, a specific dihalogen compound).
To the demand for the improvement, JP-B-4-68343 (U.S. Pat. No. 4,994,508) and JP-A-10-219040 disclose a composition comprising a block copolymer obtained by specific hydrogenation of a block copolymer of a vinyl aromatic hydrocarbon and a butadiene, and a polyolefin based resin. However, the hydrogenated block copolymer used in the present invention is not disclosed specifically in these documents, and further improvement has been required in terms of the balance between the low temperature impact resistance and the molding processability.
Furthermore, JP-B-5-69874 (U.S. Pat. No. 4,994,508) discloses a composition comprising a block copolymer obtained by specific hydrogenation of a block copolymer of a vinyl aromatic hydrocarbon and a conjugate diene based compound, and an adhesion-imparting agent. However, the hydrogenated block copolymer used in the present invention is not disclosed specifically therein, and further improvement has been required in terms of the melt viscosity stability under heating at a high temperature as well as the balance performance between the retentivity and the adhesion property.
An object of the present invention is to provide:
1) a polyolefin based resin composition having an excellent physical property balance among the impact resistance, particularly low temperature impact resistance, the rigidity, the molding processability (flowability) and the thermal resistant aging property (which composition is hereinafter referred to as an impact resistant resin composition),
2) a resin composition having excellent softness, transparency, and molding processability (which composition is hereinafter referred to as a soft resin composition),
3) a resin composition having excellent flexibility, elasticity, and molding processability (which composition is hereinafter referred to as a flexible resin composition), and
4) a viscous adhesive composition having excellent balance in adhesion characteristics such as adhesive power and retentivity, and having excellent melt viscosity stability under heating at a high temperature.
In order to achieve the above-mentioned objects, the present inventors made extensive studies. As a result, it was found that a hydrogenated block copolymer obtained by controlling, to a specific range, the hydrogenation ratio of a block copolymer of a vinyl aromatic hydrocarbon having a specific vinyl bonding amount and a conjugate diene compound provides excellent effects for improvement of a polyolefin based resin. Then, it was also found that the above-mentioned objects can be achieved effectively by a composition comprising the hydrogenated block copolymer and a polyolefin based resin, or a composition comprising the block copolymer and an adhesion-imparting agent, thereby completing the present invention. That is, the present invention provides:
1. A hydrogenated block copolymer, which is (1) a hydrogenation product of a block copolymer having at least one polymer block mainly comprising a vinyl aromatic hydrocarbon and at least one polymer block mainly comprising a conjugate diene compound, and having a vinyl bonding amount V (%) based on the conjugate diene compound of from not less than 37% to less than 70%,
wherein (a) the total hydrogenation ratio H (%) of the unsaturated double bond based on the conjugate diene compound satisfies the following relational formulae:
V less than H less than 1.25xc3x97V+10
50xe2x89xa6H less than 80, and
wherein (b) the hydrogenation ratio of the vinyl bond is 82% or more;
2. A block copolymer composition, comprising:
(1) the hydrogenated block copolymer according to item 1 above, and
(2) a polyolefin based resin;
3. The block copolymer composition according to item 2 above, comprising 1 to 50 parts by weight of component (1) and 99 to 50 parts by weight of component (2) with respect to 100 parts by weight of the total weight of components (1) and (2), wherein component (1) further satisfies the following conditions:
(c) the content of the vinyl aromatic hydrocarbon is 5 to 50% by weight, and
(d) the melt flow rate is 0.5 to 100 g/10 minutes;
4. The block copolymer composition according to item 2 above, comprising 1 to 95 parts by weight of component (1) and 99 to 5 parts by weight of component (2) with respect to 100 parts by weight of the total weight of components (1) and (2), wherein component (1) further satisfies the following conditions:
(c) the content of the vinyl aromatic hydrocarbon is 5 to 35% by weight, and
(d) the number average molecular weight is from more than 30,000 to less than 330,000;
5. The block copolymer composition according to item 2 above, comprising 20 to 95 parts by weight of component (1) and 80 to 5 parts by weight of component (2), each with respect to 100 parts by weight of the total weight of components (1) and (2), and 5 to 300 parts by weight of (3) a non-aromatic rubber softener and not more than 500 parts by weight of (4) an inorganic filler, each with respect to 100 parts by weight of component (1), wherein component (1) further satisfies the following conditions:
(c) the content of the vinyl aromatic hydrocarbon is 5 to 50% by weight, and
(d) the number average molecular weight is 50,000 to 1,000,000;
6. A block copolymer composition, comprising:
(1) 100 parts by weight of a hydrogenated block copolymer which is a hydrogenation product of a block copolymer having at least one polymer block mainly comprising a vinyl aromatic hydrocarbon and at least one polymer block mainly comprising a conjugate diene compound, and having a vinyl bonding amount V (%) based on the conjugate diene compound of from not less than 30% to less than 70%,
wherein (a) the total hydrogenation ratio H (%) of the unsaturated double bond based on the conjugate diene compound satisfies the following relational formulae:
V less than H less than 1.25xc3x97V+10
55xe2x89xa6H less than 80, and
wherein (b) the hydrogenation ratio of the vinyl bond is 82% or more, and
(2) 20 to 400 parts by weight (with respect to 100 parts by weight of component (1)) of an adhesion-imparting agent;
7. The block copolymer composition according to item 6 above, wherein component (1) further satisfies the following conditions:
(c) the content of the vinyl aromatic hydrocarbon is 5 to 60% by weight, and
(d) the peak molecular weight is 50,000 to 300,000; and
8. A block copolymer composition, comprising:
(1) 100 parts by weight of a hydrogenated block copolymer which is a hydrogenation product of a block copolymer having at least one polymer block mainly comprising a vinyl aromatic hydrocarbon and at least one polymer block mainly comprising a conjugate diene compound, and having a vinyl bonding amount V (%) based on the conjugate diene compound of from not less than 30% to less than 70%,
wherein (a) the total hydrogenation ratio H (%) of the unsaturated double bond based on the conjugate diene compound satisfies the following relational formulae:
V less than H greater than 2xc3x97V+10
30xe2x89xa6H less than 80, and
wherein (b) the hydrogenation ratio of the vinyl bond is 82% or more, and
(2) 20 to 400 parts by weight (with respect to 100 parts by weight of component (1)) of an adhesion-imparting agent,
wherein component (1) comprises:
(1-A) 20 to 90% by weight of a hydrogenated block copolymer which is a hydrogenation product of a block copolymer having one polymer block mainly comprising a vinyl aromatic hydrocarbon and one polymer block mainly comprising a conjugate diene compound, and having a vinyl bonding amount V (%) based on the conjugate diene compound of not less than 30% to less than 70%,
wherein (a) the total hydrogenation ratio H (%) of the unsaturated double bond based on the conjugate diene compound satisfies the following relational formulae:
V less than H less than 2xc3x97V+10
30xe2x89xa6H less than 80,
wherein (b) the hydrogenation ratio of the vinyl bond is 82% or more, and
wherein (c) the content of the vinyl aromatic hydrocarbon is 5 to 60% by weight; and
(1-B) 80 to 10% by weight of a hydrogenated block copolymer which is a hydrogenation product of a block copolymer having at least two polymer blocks mainly comprising a vinyl aromatic hydrocarbon and at least one polymer block mainly comprising a conjugate diene compound, and having a vinyl bonding amount V (%) based on the conjugate diene compound of from not less than 30% to less than 70%,
wherein (a) the total hydrogenation ratio H (%) of the unsaturated double bond based on the conjugate diene compound satisfies the following relational formulae:
V less than H less than 2xc3x97V+10
30xe2x89xa6H less than 80,
wherein (b) the hydrogenation ratio of the vinyl bond is 82% or more, and
wherein (c) the content of the vinyl aromatic hydrocarbon is 5 to 60% by weight,
wherein the average molecular weight of component (1-A) and component (1-B) is 50,000 to 300,000.